Power operated knife



Dec. 12, 1967 H. KORSHAK POWER OPERATED KNIFE 2 Sheets-Sheet 1 FiledSept. 1, 1965 .K RA 8 B 3 1.\ n mm H rm- N 9 .Iiialv SN \9 1 l n V m w Ra Q n q H V TQ ATTORNEY H. KORSHAK Dec. 12, 1967 POWER OPERATED KNIFE 2Sheets-Sheet Filed Sept. 1, 1965 INVENTOR HARVEY KORSHAK ATTORNEY UnitedStates Patent 3,357,102 POWER OPERATED KNIFE Harvey Korshak, Skokie,Ill., assignor to Scovill Manufacturing Company, Waterbury, Conn., acorporation of Connecticut Filed Sept. 1, 1965, Ser. No. 484,370 Claims.(Cl. 30-272) This invention relates to a power operated knife andparticularly to mechanism for reciprocating a pair of knife bladeslongitudinally relatively to each other.

One of the objects of the invention is to provide an integrally formedgear and crank unit for imparting reciprocatory motion to a pair ofdriver bars and carriers in which the blades are detachably mounted.

Another object is to provide a gear bracket in which the combinationgear and crank unit is mounted.

Another object is to provide anti-friction means in the gear bracket forfree smooth movement of the driver bars relatively to the bracket, andto provide anti-friction means ina front guide member for frictionlessmovement 3 of the blade carriers relatively to the guide when the connected driver bars and blade carriers are reciprocated by the cranks.

Other objects and advantages will appear from the drawings and followingdescription.

In the drawings:

FIG. 1 is a longitudinal vertical sectional view, partly in elevation,on an enlarged scale, of the forward end of a power operated knifeembodying my invention, the knife blades being omitted.

FIG. 2 is a top plan view of the mechanism shown in FIG. 1, with theupper housing removed.

FIG. 3 is a transverse vertical sectional view in the plane of the line33 of FIG. 1.

FIG. 4 is a transverse vertical sectional view in the plane of the line4-4 of FIG. 2.

FIG. 5 is a transverse vertical sectional view in the plane of the line55 of FIG. 1.

FIG. 6 is an elevational side view of the integral gear and crank unitas viewed in the plane of the line 66 of FIG. 4.

FIG. 7 is an elevational side view of the integral gear and crank unitas it appears in the plane of the line 77 of FIG. 4.

In that embodiment of the invention shown in the drawings, a housing 10encloses a motor 11, motor shaft 12, driver bars 13, 13 connected toblade carriers 14, 14, and driving mechanism located between the motorand the driver bars for imparting reciprocatory motion to the connecteddriver bars and carriers. Tangs 15, 15, of knife blades (not shown) aremounted in and retained by the carriers 14.

The driving mechanism comprises a pinion 20 and spacer 19 fixed on themotor shaft 12, the pinion meshing with a bevel gear 21 formedintegrally with a hub 22 provided with cranks 23, 24 at opposite ends.The hub 22 is loosely mounted on a transversely extending shaft 25. Theshaft 25 is mounted at opposite ends in a gear bracket comprising averticaly disposed back plate 26, with motor shaft bearing 27,circumferential flange 28, and a pair of forwardly extending side arms29, 29. The arms 29 are provided with registering apertures forreception of the ends of the shaft 25, and are spaced apart to receivebetween them the integral unit consisting of the gear 21, hub 22 andcranks 23, 24, as shown in FIGS. 2 and 4.

The gear bracket back plate 26 is retained in the position shown in FIG.1 by the support 30 in housing 10 and by upper and lower hook ended leafsprings 31, 31,

which overlie the motor 11 and engage the flange 28 of the gear bracket.

The back plate flange 28 of the gear bracket, below the arms 29, isprovided with an aperture or recess 32 at each side for mounting thereina transverse shaft 33 (FIGS. 1 and 5) staked to the plate at 34. A pairof rollers 35 are rotatable on the shaft 33 in such position that thedriver bars 13 rest on the rollers for free smooth movement thereoverwhen the driver bars are reciprocated by the mechanism describedhereinafter. Projections for guiding the driver bars are indicated at36.

The driver bars 13 are flat and rectangular in cross section in theirrearward portion as shown in FIG. 5. In the median portion 40, each ofthe driver bars widens from top to bottom and is provided with anopening 41 as shown in FIGS. 1 and 4. The opening is wide enough toreceive one of the cranks 23 or 24 between the vertical parallel edgesof the opening 41. The opening 41 is deep enough from top to bottom toaccommodate the eccentric movement of the cranks 23, 24, as shown inFIG. 4. The forward ends of the driver bars 13 are connected to theblade carriers 14 in which are mounted the blade tangs 15. Thusreciprocatory motion is transmitted to the driver bars, carriers andblade tangs by rotation of the motor shaft 12, pinion 20, gear 21, hub22 and cranks 23, 24, engaging the driver bars 13 through the openings41 in the portion 40 of said bars.

The carriers 14, as shown in section in FIG. 3, are movablelongitudinally in a front guide 50 in the end of the housing 10.Antifriction rollers 51 are loosely mounted on the transverse shaft 52fixedly mounted in guide 50 for hearing on the carriers 14. The frontguide 50 is fastened in the housing by a rivet 53.

The gear and crank unit, mounted in its special gear bracket, provides acompact easily assembled means for translating the rotary motion of themotor shaft into reciprocatory movements in opposite directions of theblade drivers, carriers and blade tangs. The anti-friction means mountedin the gear bracket and in the front guide permit guided frictionlessmovements of the driver bars and carriers in predetermined planes.

Changes may be made in details of construction and form an arrangementof parts without departing from the scope of the invention as defined bythe appended claims.

I claim:

1. In a power operated knife having a housing, a motor, motor shaft, apair of driver bars, a pair of blade carriers connected to the bars, anda pair of knife blades having tangs mounted in the carriers, mechanismbetween the motor and driver bars for reciprocating the driver bars,carriers and blades comprising (a) a pinion fixed on the motor shaft,

(b) a gear assembly including a transversely extending shaft, and anintegral bevel gear, hub and cranks at opposite ends of the hub mountedon the transverse shaft,

(c) a gear bracket connected to the motor comprising a back plateextending transversely of the housing and radially of the motor shaftbetween the motor and the pinion, and a pair of arms extending forwardlyfrom the back plate and spaced apart to receive the gear assemblybetween the arms and with the transverse shaft mounted in the arms andthe pinion meshing with the bevel gear,

(d) a hook ended leaf spring overlying the motor and engaging the backplate of the bracket, and

(e) means on the driver bars engaged by said cranks for impartingreciprocatory movement to the driver bars when the bevel gear is rotatedby the pinion.

2. In a power operated knife having a housing, a motor, motor shaft, apair of blade carriers, and a pair of knife blades having tangs mountedin the carriers, mechanism between the motor and carriers forreciprocating the carriers and blades comprising (a) a pinion fixed onthe motor shaft,

(b) a gear assembly including a transversely extending shaft, and anintegral bevel gear, hub and cranks at opposite ends of the hub mountedon the transverse shaft,

(c) a gear bracket comprising a back plate extending transversely of thehousing and radially of the motor shaft between the motor and thepinion, and a pair of arms extending forwardly from the back plate andspaced apart to receive the gear assembly between the arms with thetransverse shaft mounted in the arms and the pinion meshing with thebevel gear,

(d) said gear bracket back plate having slots therein and a rollermounted adjacent each slot for passage of the carriers over said rollersand through said slots, and

(e) means on the carriers engaged by said cranks for impartingreciprocatory movement to the carriers when the bevel gear is rotated bythe pinion.

3. In a power operated knife having a housing, a motor, motor shaft, apair of driver bars, a pair of blade carriers connected to the bars, anda pair of knife blades having tangs mounted in the carriers, mechanismbetween the motor and driver bars for reciprocating the driver bars,carriers and blades comprising (a) a pinion fixed on the motor shaft,

(b) a gear assembly including a transversely extending shaft, and anintegral bevel gear, hub and cranks at opposite ends of the hub mountedon the transverse shaft,

(c) a gear bracket comprising a back plate extending transversely of thehousing and radially of the motor shaft between the motor and thepinion, and a pair of arms extending forwardly from the back plate andspaced apart to receive the gear assembly between the arms with thetransverse shaft mounted in the arms and the pinion meshing with thebevel gear, ((1) said gear bracket back plate having slots therein and aroller mounted adjacent each slot for passage of the driver bars oversaid rollers and through said slots, and (e) means on the driver barsengaged by said cranks for imparting reciprocatory movement to thedriver bars when the bevel gear is rotated by the pinion. 4. The poweroperated knife defined by claim 3 which includes a front guide fixed onthe housing, a roller on a transversely extending shaft in said frontguide for engaging the blade carriers.

5. A power operated knife comprising (a) a motor shaft,

(b) a pair of driver bars and blade carriers,

(c) means operatively connecting the motor shaft and the driver bars andblade carriers for transmitting reciprocatory movements to said driverbars and carriers,

(d) a bracket connected to the motor and extending transversely of themotor shaft provided with slots through which the driver bars pass whenreciprocated, and

(e) rollers mounted adjacent said slots and beneath said driver bars formovement of the bars over the rollers.

References Cited UNITED STATES PATENTS 1,826,187 10/1931 Pickering 143682,764,188 9/1956 Hoffman 14368 3,203,095 '8/ 1965 Nelson 30-2723,203,096 8/1965 Beisheim et al 30--272 FOREIGN PATENTS 1914 GreatBritain.

JAMES L. JONES, 311., Primary Examiner.

1. IN A POWER OPERATED KNIFE HAVING A HOUSING, A MOTOR, MOTOR SHAFT, APAIR OF DRIVER BARS, A PAIR OF BLADE CARRIERS CONNECTED TO THE BARS, ANDA PAIR OF KNIFE BLADES HAVING TANGS MOUNTED IN THE CARRIERS, MECHANISMBETWEEN THE MOTOR AND DRIVER BARS FOR RECIPROCATING THE DRIVER BARS,CARRIERS AND BLADES COMPRISING (A) A PINION FIXED ON THE MOTOR SHAFT,(B) A GEAR ASSEMBLY INCLUDING A TRANSVERSELY EXTENDING SHAFT, AND ANINTEGRAL BEVEL GEAR, HUB AND CRANKS AT OPPOSITE ENDS OF THE HUB MOUNTEDON THE TRANSVERSE SHAFT, (C) A GEAR BRACKET CONNECTED TO THE MOTORCOMPRISING A BACK PLATE EXTENDING TRANSVERSELY OF THE HOUSING ANDRADIALLY OF THE MOTOR SHAFT BETWEEN THE MOTOR AND THE PINION, AND A PAIROF ARMS EXTENDING FORWARDLY FROM THE BACK PLATE AND SPACED APART TORECEIVE THE GEAR ASSEMBLY BETWEEN THE ARMS AND WITH THE TRANSVERSE SHAFTMOUNTED IN THE ARMS AND THE PINION MESHING WITH THE BEVEL GEAR, (D) AHOOK ENDED LEAF SPRING OVERLYING THE MOTOR AND ENGAGING THE BACK PLATEOF THE BRACKET, AND (E) MEANS ON THE DRIVER BARS ENGAGED BY SAID CRANKSFOR IMPARTING RECIPROCATORY MOVEMENT TO THE DRIVER BARS WHEN THE BEVELGEAR IS ROTATED BY THE PINION.